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White LED (White Light Emitting Diodes) Circuits
White LEDs:  #'s - D         E - O         P - S         T - Z         LED Circuits

 

Last Updated: June 02, 2021 01:45 PM

Circuits Designed by Dave Johnson, P.E. :

Pot Controlled Variable LED Intensity Circuit - The circuit below uses power from four rechargeable AA NiMH cells to drive 3 white LEDs.  A potentiometer varies the duty cycle of a pulse width modulator circuit to vary the intensity of the LEDs from 0% to 100%.  The beauty of the circuit is that when the. . . Circuit by Dave Johnson P.E.-September, 2009

Simple Circuit for White LED Night Light - This simple circuit is designed to plug into a standard AC electrical outlet.  It uses four super bright white light emitting diodes (LED) in conjunction with a capacitor coupled full wave rectifier circuit. . . Circuit by David A. Johnson P.E.-July, 2003

Solid State Relay that is Bidirectional - The circuit below can switch up to 4 amps of current with a peak voltage up to 20v.  It is fully isolated using two inexpensive red LEDs.  One LED forms a red light source, which illuminates a second red LED.  The circuit takes advantage of the 1.5v . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2009

Solar-Powered_LED_Light_for_Tool_Shed  -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July 14, 2017


Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

Perpetual Candle-White LED Lamp on Ni-Cd -  This is a easy to build LED lamp circuit for Learning and building skills.  This is the first draft schematic V 1.0.  It will need improvements for Higher Power Lighting.  Click to enlarge I will give a short summary, The LM317 here configured for

Picnic Lamp -  You can take this white LED based night lamp on your picnic outings.  The lamp has sound trigger and push-to-on facilities and gives ample light during a walk at night.  It...__ Electronics Projects for You

Pocket white-LED torch is power efficient -  04/30/13  EDN-Design Ideas This single white-LED torch can be housed in an empty glue-stick tube and has a long rechargeable-battery life.   Design by Raju Baddi

Provide High-Side Current-Sensing for White-LED Drivers -  02/19/04  EDN-Design Ideas White LEDs find wide use in backlighting color-LCD screens in most portable devices, such as cellular phones, PDAs, and MP3 players.  Multiple LEDs often connect in series to ensure that the same current flows through every LED.  To  Design by Dimitry Goder, Sipex Corp, San Jose, CA

Rechargeable Torch Based On White Led -  Rechargeable torches donít come without problems.  You need to replace the bulbs and charge the batteries frequently.  The average incandescent light-emitting diode  (LED) based torch, for instance, consumes around 2 watts....__ Electronics Projects for You

Regulated 20 mA Dual White LED Lamp -  This is an ultra-simple LED spot lamp that consists of two LEDs and a current regulator circuit. It is designed for use in 12V solar powered lighting applications and can be used in cars, boats, RVs and even fountains. Only seven components are required. The circuit produces non-flickering regulated light with an input of 11 to 20 volts. If the lamp is potted in Silicone caulk, it will be completely waterproof. The circuit will support either 20mA, 25mA and 30mA LEDs by changing the value of one resistor. __ Designed by G. Forrest Cook

Regulated 24 Watt Broad Spectrum LED Lamp -  ultra-bright __ Designed by G. Forrest Cook

Regulated Dual 3 Watt White LED Lamp -  Simple, reliable regulated night light __ Designed by G. Forrest Cook

Rotary Encoder Mates with Digital Potentiometer -  6-Mar-03 EDN-Design Ideas Buck IC boosts battery voltage for white LEDIn developing electronic systems, designers look for products or ideas that may benefit from the better performance, smaller size, lower cost, and improved reliability that an IC can offer.  Toward that end, the digital potentiometer emerged as an alternative to its mechanical counterpart, the mechanical potentiometer Design by Peter Khairolomour, Analog Devices, San Jose, CA

Scheme provides high-side current-sensing for white-LED drivers -  19-Feb-04 EDN-Design Ideas White LEDs find wide use in backlighting color-LCD screens in most portable devices, such as cellular phones, PDAs, and MP3 players.  Multiple LEDs often connect in series to ensure that the same current flows through every LED.  To forward-bias these LEDs, a voltage of 10 to 16V comes from an inductor-based boost regulator, such as an SP6690 Design by Dimitry Goder, Sipex Corp, San Jose, CA

Self-Oscillating H Bridge Lights White LED From One Cell -  26-Nov-09 EDN-Design Ideas Circuit operates on batteries as low as 0.6V Design by Luca Bruno, ITIS Hensemberger Monza, Lissone, Italy

Series Connected Voltage Boost for a Battery Operated LED Lantern -  A circuit that goes in series with a white LED and a 1.5 volt cell to make > 3 Volts to drive a white LED __ Designed by Dick Cappels

Seven Component Regulated LED Lamp -  This is a minimal parts lamp made with four white LEDs.  It features regulated light output from 10V to around 20V and works well as a flashlight.   __ Designed by G. Forrest Cook

Simple Circuit drives latching relays -  02/01/96 EDN-Design Ideas Figure 1 shows a low-parts-count circuit that can drive one- or two-coil latching relays.  Latching relays are useful in sensitive analog designs.  The 74ACT174 hex flip-flop has ample capability to drive the Aromat TQ2E series of latching relays.  Both windings for the TQ2E-L2-5V two-coil relay are on the same magnetic element, so the windings' fields add.  You Design by Roy McCammon, 3M Austin, TX

Simple Circuit for White LED Night Light -  This simple circuit is designed to plug into a standard AC electrical outlet.  It uses four super bright white light emitting diodes  (LED) in conjunction with a capacitor coupled full wave rectifier circuit. . . Circuit by David A. Johnson P.E.-July, 2003

Simple Circuit single-cell white-LED driver uses improvised transformer -  15-Feb-07 EDN-Design Ideas Minimal component-count circuit boosts a single cell's voltage to light an LED Design by Jim Grant, Scientific Controls, Orlando, FL

Simplified white-LED flasher operates from one cell -  26-May-05 EDN-Design Ideas 1.5V circuit flashes white LED Design by Anthony H Smith, Scitech, Biddenham, England

Single & Two Cell White LED Drivers Without Inductors -  The operating voltage of white LEDs coupled with my emotional need for low cost for a given function, motivates me to make LED drivers suitable for battery operated lanterns that can run from a small number of cells.  White and Ultraviolet LEDs __ Designed by Dick Cappels

Single Cell Flashes White LED -  12/11/03 EDN-Design Ideas Many portable appliances and other products that must operate from a single cell are restricted to working at very low voltages.  It is thus difficult to drive white LEDs that typically have a forward voltage of 3 to 5V.  The ability Design by Anthony Smith, Scitech, Biddenham, Bedfordshire, UK

Single-Cell White-LED Driver Uses Improvised Transformer -  02/01/07  EDN-Design Ideas Minimal component-count circuit boosts a single cell's voltage to light an LED. Design by Jim Grant

Solar-Powered_LED_Light_for_Tool_Shed  -  I have a lean-to 8ft by 12ft shed next to my house.  It is full of lawn chemicals and garden supplies.  There were times when I needed to get something from inside the shed during the dead of night.  Early on I had to use a flashlight.  But later, I installed a series of five 12v LED light strips on the ceiling.  Each strip contained 15 3v white LEDs.  The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Hobby Circuit by David Johnson P.E.-July 14, 2017

Solar Charged LED Utility Light -  Tired of always spending money on flashlight batteries only to have them fail just when you need them? Try this simple circuit out.  It would make an excellent science fair project.  The white LEDs are quite bright, they provide enough light to illuminate a small room at night.  The LEDs produce a nicely focused beam.  You can read by the light of this device.   __ Designed by G. Forrest Cook

Solar Powered Night Light -  The goal of this project was to produce a self contained reading lamp that could be used by students in developing countries for reading at night.  The circuit can be used for a wide variety of lighting applications __ Designed by G. Forrest Cook

Solar Powered Reading Lamp -  The goal of this project was to produce a self contained reading lamp that could be used by students in developing countries for reading at night.  The circuit can be used for a wide variety of lighting applications __ Designed by G. Forrest Cook

Solid State Relay that is Bidirectional -  The circuit below can switch up to 4 amps of current with a peak voltage up to 20v.  It is fully isolated using two inexpensive red LEDs.  One LED forms a red light source, which illuminates a second red LED.  The circuit takes advantage of the 1.5v . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2009

Synchronous Buck/Boost High Power White LED Driver -  LT3453__ Linear Technology/Analog Devices


White LEDs:  #'s - D         E - O         P - S         T - Z         LED Circuits


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